This application is the national phase under 35 U.S.C. xc2xa7371 of PCT International Application No. PCT/CH97/00396 which has an International filing date of Oct. 21, 1997 which designated the United States of America.
The invention relates to a method for measuring the mechanical data of a graded and tampered soil, or a soil that is to be graded and tampered, to a grading and tampering method in order to achieve optimal, in particular, homogeneous grading and tampering of a soil, to an apparatus for measuring the mechanical data of a graded and tampered soil, or of a soil that is to be graded and tampered, and to an apparatus for grading and tampering a soil in order to achieve optimal, homogeneous compacting of that soil.
A method for soil grading and tampering is known in the art from WO 95/10664. With this known method, the frequency of a rotating unbalance is adjusted in such a way that the grader and tamper unit, which has contact with the ground that is to be graded and tampered, will not exceed a preset harmonic oscillation value - here twice the value of the fundamental oscillation. Staying below this preset value is defined as a stability criterion. Using two acceleration recorders, arranged vertically to each other on the grader and tamper unit, their accelerations are measured. One acceleration recorder measures the horizontal, the other measures the vertical acceleration component. Determined are the oscillation amplitude of the grader and tamper device, and the direction of the maximum compacting amplitude. The frequency of the eccentric, as well as its weight and the rolling speed are adjustable with the aid of a computer. However, these values are adjusted in such a way so as to avoid machine and chassis resonance. Adjustment of the eccentric""s frequency and weight is carried out without accounting for the qualities of the soil that is to be graded and tampered. Based on the measured acceleration values, the modulus of elasticity in shear of the compacted soil and its plastic parameter are determined.
Another method for soil grading and tampering is known in the art from EP-A 0 459 062. With this known grading and tampering method, emphasis is placed on adjusting the machine parameters in such a manner that preset forces acting upon the the soil, which is to be graded and tampered, are achieved.
The object of the invention is to describe a method for measuring and/or grading and tampering a soil, and to create an apparatus for measuring and/or grading and tampering a soil which allows homogeneous soil compacting by using a grading and tampering method that requires as few equipment runs as possible; in particular, with a preset, desired soil rigidity and/or, in particular, a desired modulus of elasticity, and which allows the determination of mechanical data for the soil to be graded and tampered, or the graded and tampered soil.
The object of the invention is realized in that, in contrast to patent WO 95/10664, reliance is not placed on the local phase position of a maximum oscillation amplitude of a grading and tampering or measuring device, but instead reliance is placed on the temporal phase of the exciting oscillation of the eccentric(s) in relation to the phase of the excited oscillation of the soil grading and tampering and/or measuring systems, which is identical to the oscillation of the grading and tampering and/or the measuring devices. Also contrary to WO 95/10664, work is performed in the resonant range of an oscillation system, which consists of the grader and tamper or measuring device, acting upon the soil that is to be compacted (or has been compacted), and the soil. Although the soil grader and tamper apparatus described in EP-A 0 459 062 operates in the resonant range of its grader and tamper device, it is unable, however, to determine the soil rigidity CB, which is reached with the compacting process, and is therefore not able to optimize the compacting process on the basis of these established values.